A vehicle has an emission control system in which a purge control solenoid valve (PCSV) is installed between an intake manifold and a canister to control fuel evaporation gas collected at the canister.
The canister collects the fuel evaporation gas to flow into a surge tank through the PCSV that is controlled by an engine control unit (ECU) which receives information from sensors, such as a coolant temperature sensor, an oxygen sensor, etc.
Then, the fuel evaporation gas, which is detrimental, is combusted and prevented from being discharged into the atmosphere.
The PCSV can be classified into a duty control type PCSV which is controlled by the ECU and an on/off control type PCSV which is controlled by negative pressure of an intake manifold and the ECU, and the PCSV is generally closed under low coolant temperature or engine idling.
When an engine operates in a normal temperature range, the PCSV is opened and the fuel evaporation gas collected at the canister flows through a vapor hose into the intake manifold to be combusted.
Whenever the PCSV is opened and closed by an actuator, operating noise is generated and transferred in the reverse direction to an inflow direction of the fuel evaporation gas through the vapor hose which connects the PCSV and the canister.
Further, pulsation noise is generated due to pulsating of the fuel evaporation gas passing through the PCSV and transferred through the vapor hose in the reverse direction to a pulsating direction.
In general, the operating noise of the PCSV and the pulsation noise transfer to a driver's seat through the vapor hose because the vapor hose connects the canister and the PCSV and transfers the noise to a dash panel disposed in front of the driver's seat.
Thus, during engine idling and driving at a low speed, noises are generated.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.